Galvanic Corrosion of Piping and Fitting Alloys in Sulfide-Modified Seawater

Two wrought piping alloys, 70-30 and 90-10 copper-nickel, were each galvanically coupled to each of four fitting alloys in sulfide-modified seawater for 30 days. The fitting alloys used were bronze Composition M, cast Monel, wrought nickel-aluminum bronze, and cast 70-30 copper-nickel. The piping materialfitting material area ratio was 31, and the seawater velocity was 2.4 meters per second. Results indicated that the galvanic relationship between M- bronze or Monel and 70-30 copper-nickel is affected by sulfide additions in a manner that increases the corrosion of the fitting material, whereas similar couples with 90-10 copper-nickel show little effect of sulfide.